The present invention relates to a seat, particularly to a vehicle seat in which a pad assembly is covered with a cover assembly.
In a vehicle seat such as a front seat of a vehicle in the related art, side portions contiguous to the opposite sides of a main portion that is interposed between the side portions are formed as somewhat high banks. A method using pulling wires as shown in FIGS. 5 and 6 prevails in covering of such a seat. In this case, a cover assembly 11 having side portions 11a and a main portion 11b seamed together in their boundary portion is put over a pad assembly 12. Thus, a vehicle seat is formed.
In such a vehicle seat, each bank-like side portion is higher than the main portion. Therefore, unless the boundary portions (concave shapes) between the side portions 11a and the main portion 11b of the cover assembly 11 and the intermediate portion of the main portion 11b are fixed, the cover assembly 11 may rise away from the pad assembly 12 in the boundary portions and in the intermediate portion. Thus, the exterior appearance may be degraded. To prevent such a problem, the following structure is adopted.
That is, FIG. 5 is a perspective view of a seat viewed from above the seat (from the front side) for explaining a vehicle seat covering method in the related art, and FIG. 6 is a perspective view of the arrangement of end wires viewed from above the seat (from the front side).
In the pad assembly 12, boundary-portion pulling slots 12c and 12c for pulling the cover assembly 11 are formed in the boundary portions between the opposite side portions 12a and the main portion 12b so as to extend in the front/rear direction, while a main-portion pulling slot 12d is formed in the intermediate portion of the main portion 12b so as to extend in a direction crossing the boundary-portion pulling slots 12c and 12c. 
Boundary-portion insert wires 16 and 16 and a main-portion insert wire 17 are embedded in the bottom portions of the pulling slots 12c, 12c and 12d respectively.
On the other hand, boundary-portion pulling bags 11c and 11c and a main-portion pulling bag 11d each having a cylindrical shape are sewn on the back of the cover assembly 11.
The boundary-portion pulling bags 11c and 11c are pulled into the boundary-portion pulling slots 12c and 12c of the pad assembly 12, while the main-portion pulling bag 11d is pulled into the main-portion pulling slot 12d of the pad assembly 12.
The boundary-portion pulling bags 11c and 11c are sewn and paired left and right to be located in the boundary portions between the opposite side portions 11a and the main portion 11b in the cover assembly 11 respectively. Each of the left and right boundary-portion pulling bags 11c and 11c is divided into two in the front/rear direction of the seat.
Boundary-portion end wires 14 and 15 shown in FIG. 6 and corresponding to boundary-portion insert wires 16 and 16 are inserted into the divided pieces of each of the left and right boundary-portion pulling bags 11c and 11c.
On the other hand, a main-portion end wire 13 shown in FIG. 6 and corresponding to the main-portion insert wire 17 is inserted into the main-portion pulling bag 11d. 
The vehicle seat is assembled as follows. That is, the cover assembly 11 is put over the surface of the pad assembly 12. Then, the boundary-portion pulling bags 11c and 11c having the boundary-portion end wires 14 and 15 inserted thereto on the opposite sides are pulled into the boundary-portion pulling slots 12c and 12c of the pad assembly 12. On the other hand, the main-portion pulling bag 11d having the main-portion end wire 13 inserted thereto is pulled into the main-portion pulling slot 12d of the pad assembly 12. Then, the boundary-portion end wires 14 and 15 on the opposite sides are fixed to the boundary-portion insert wires 16 and 16 of the pad assembly 12. On the other hand, the main-portion end wire 13 is fixed to the main-portion insert wire 17 of the pad assembly 12.
The fixation of the wires 13, 14 and 15 to the wires 17, 16 and 16 is performed by pulling hog rings 18 such as C-rings on the insert wires 17, 16, and 16 corresponding to the end wires 13, 14 and 15 as shown by the arrows in FIG. 5. When the hog rings 18 are used, each end wire 13, 14, 15 and each insert wire 17, 16, 16 are fixed at a plurality of places in their length direction because of the necessity of preventing the cover assembly 11 from rising away from the pad assembly 12. In FIG. 5, fixation on each boundary-portion insert wire 16, 16 is performed at four places, and fixation on the main-portion insert wire 17 is performed at two places. Thus, fixation is performed at 10 placed in total.
Such a technique in the related art has the following problems.
A complicated configuration as described above is required for preventing the cover assembly from rising away from the pad assembly in the boundary portions (concave shapes) between the main portion and the side portions of the seat.
Recently, in order to improve the exterior appearance of the seat, there is a tendency to make the bank portions higher, make the pulling slots deeper (deeper pulling) and made the pulling slot narrower. Thus, the workability in pulling and fixation using a hog ring gun, that is a tool for the hog rings, becomes worse and worse.
Thus, there is a problem that the cost and the weight increases due to a large number of complicated constituent parts for pulling, and the number of man-hours for the work of pulling is large.